1 files changed, 132 insertions, 0 deletions

diff --git a/drivers/media/video/videobuf2-vmalloc.c b/drivers/media/video/videobuf2-vmalloc.c
new file mode 100644
index 000000000000..a3a884234059
--- /dev/null
+++ b/drivers/media/video/videobuf2-vmalloc.c
@@ -0,0 +1,132 @@
+/*
+ * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <pawel@osciak.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_vmalloc_buf {
+        void                            *vaddr;
+        unsigned long                   size;
+        atomic_t                        refcount;
+        struct vb2_vmarea_handler       handler;
+};
+
+static void vb2_vmalloc_put(void *buf_priv);
+
+static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size)
+{
+        struct vb2_vmalloc_buf *buf;
+
+        buf = kzalloc(sizeof *buf, GFP_KERNEL);
+        if (!buf)
+                return NULL;
+
+        buf->size = size;
+        buf->vaddr = vmalloc_user(buf->size);
+        buf->handler.refcount = &buf->refcount;
+        buf->handler.put = vb2_vmalloc_put;
+        buf->handler.arg = buf;
+
+        if (!buf->vaddr) {
+                printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size);
+                kfree(buf);
+                return NULL;
+        }
+
+        atomic_inc(&buf->refcount);
+        printk(KERN_DEBUG "Allocated vmalloc buffer of size %ld at vaddr=%p\n",
+                        buf->size, buf->vaddr);
+
+        return buf;
+}
+
+static void vb2_vmalloc_put(void *buf_priv)
+{
+        struct vb2_vmalloc_buf *buf = buf_priv;
+
+        if (atomic_dec_and_test(&buf->refcount)) {
+                printk(KERN_DEBUG "%s: Freeing vmalloc mem at vaddr=%p\n",
+                        __func__, buf->vaddr);
+                vfree(buf->vaddr);
+                kfree(buf);
+        }
+}
+
+static void *vb2_vmalloc_vaddr(void *buf_priv)
+{
+        struct vb2_vmalloc_buf *buf = buf_priv;
+
+        BUG_ON(!buf);
+
+        if (!buf->vaddr) {
+                printk(KERN_ERR "Address of an unallocated plane requested\n");
+                return NULL;
+        }
+
+        return buf->vaddr;
+}
+
+static unsigned int vb2_vmalloc_num_users(void *buf_priv)
+{
+        struct vb2_vmalloc_buf *buf = buf_priv;
+        return atomic_read(&buf->refcount);
+}
+
+static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+        struct vb2_vmalloc_buf *buf = buf_priv;
+        int ret;
+
+        if (!buf) {
+                printk(KERN_ERR "No memory to map\n");
+                return -EINVAL;
+        }
+
+        ret = remap_vmalloc_range(vma, buf->vaddr, 0);
+        if (ret) {
+                printk(KERN_ERR "Remapping vmalloc memory, error: %d\n", ret);
+                return ret;
+        }
+
+        /*
+         * Make sure that vm_areas for 2 buffers won't be merged together
+         */
+        vma->vm_flags           |= VM_DONTEXPAND;
+
+        /*
+         * Use common vm_area operations to track buffer refcount.
+         */
+        vma->vm_private_data    = &buf->handler;
+        vma->vm_ops             = &vb2_common_vm_ops;
+
+        vma->vm_ops->open(vma);
+
+        return 0;
+}
+
+const struct vb2_mem_ops vb2_vmalloc_memops = {
+        .alloc          = vb2_vmalloc_alloc,
+        .put            = vb2_vmalloc_put,
+        .vaddr          = vb2_vmalloc_vaddr,
+        .mmap           = vb2_vmalloc_mmap,
+        .num_users      = vb2_vmalloc_num_users,
+};
+EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
+
+MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
+MODULE_LICENSE("GPL");